International Grape Genome Program

Last updated
The IGGP's main goals are to improve control, yield and quality in wine grape production via genetic modification. Pinot Gris close.JPG
The IGGP's main goals are to improve control, yield and quality in wine grape production via genetic modification.

The International Grape Genomics Program (IGGP) is a collaborative genome project dedicated to determining the genome sequence of the grapevine Vitis vinifera . It is a multinational project involving research centers in Australia, Canada, Chile, France, Germany, Italy, South Africa, Spain, and the United States.

Contents

The project was established on the premise that whereas the Vitis family provides the world's most economically important fruit, its biology is still poorly understood. Many centuries of viticulture have provided many well-informed wine-producing centres throughout the world, yet exactly how a grapevine plant responds and interacts with the physical environment and deals with abiotic stresses, pests and diseases is currently unknown.

Agricultural technology surrounding Vitis has been traditionally based upon specific genotypes, which in the main have relied on "vegetative multiplication" and control of growing conditions to improve quality and yield. While advances in quality have certainly been achieved, it has involved increased costs and is in danger of incurring unsustainable environmental overheads. The argument is that the relatively unknown biology of Vitis is capable of delivering desired viticultural improvements without the associated ongoing costs, and establishing its genome sequence will examine the role individual genes play in viticulture, improving grape characteristics and quality in a predictable way. [1]

Initial discoveries

As of March 2007, the project has mapped over half of the grapevine genome. In the course of their research, the Cooperative Research Centre for Viticulture (CRCV), based at the CSIRO Plant Industry Horticulture Unit in Adelaide, Australia (one of the IGGP collaborating centres) discovered that white grapes only exist today as a result of a rare genetic mutation which took place thousands of years ago. White grapes are believed to have arisen due to the extremely rare and independent mutation of two similar and adjacent regulatory genes, VvMYBA1 and VvMYBA2, in a red grape parent.

Most grapevine cultivars can be divided into two groups – red and white – based on the presence or absence of anthocyanin in the skin of the fruit, which the geneticists discovered to be controlled by these two genes. Although either can dictate colour, the VvMYBA1 gene, which activates the anthocyanin biosynthesis necessary to produce red grapes, was shown not to be transcribed in white grape berries. The white berry allele of VvMYBA2 was inactivated by two mutations, one leading to an amino acid substitution and the other to a frameshift mutation. Tests showed that either mutation removes the ability of the regulator to switch on anthocyanin biosynthesis, and when both are switched off it results in a white cultivar. Sequence analyses of the VvMYBA2 gene confirmed that all of the 55 white cultivars tested contained the white berry allele, but not red berry alleles – and all displayed exactly the same double mutation, pointing to a single, common ancestor. [2] Assuming this to be true of all white cultivars, without this single parent vine there would be no white grapes today. White wine residues discovered in ancient Egyptian pottery remains suggest that this mutation occurred at least three thousand years ago, [3] although in lieu of testing against a known white grape genome, the possibility remains that the mutation could have occurred more recently.

A similar dual mutation occurred during the last decade. Viticultor Jesús Galilea Esteban, of the vineyard Murillo de Rio Leza in Rioja, Spain, noticed a white grape mutation in some Tempranillo grapevines growing on his estate. After the white vine was propagated and the mutation did not revert, the new varietal was granted outline permission to apply for approved grape status by the Rioja D.O. and the first hectare of white Tempranillo was planted in the region in the year 2000. Both white and red vines share identical leaves, clusters and berry shape, as well as the short ripening cycles and sensitivity to pests and diseases typical of the red Tempranillo. The mutation is thought to have occurred as a result of environmental factors. [4]

See also

Related Research Articles

<span class="mw-page-title-main">Grape</span> Fruit growing on woody vines in clusters

A grape is a fruit, botanically a berry, of the deciduous woody vines of the flowering plant genus Vitis. Grapes are a non-climacteric type of fruit, generally occurring in clusters.

<span class="mw-page-title-main">Cabernet Sauvignon</span> Red-wine variety of grape

Cabernet Sauvignon is one of the world's most widely recognized red wine grape varieties. It is grown in nearly every major wine producing country among a diverse spectrum of climates from Australia and British Columbia, Canada to Lebanon's Beqaa Valley. Cabernet Sauvignon became internationally recognized through its prominence in Bordeaux wines, where it is often blended with Merlot and Cabernet Franc. From France and Spain, the grape spread across Europe and to the New World where it found new homes in places like California's Santa Cruz Mountains, Paso Robles, Napa Valley, New Zealand's Hawke's Bay, South Africa's Stellenbosch region, Australia's Margaret River, McLaren Vale and Coonawarra regions, and Chile's Maipo Valley and Colchagua. For most of the 20th century, it was the world's most widely planted premium red wine grape until it was surpassed by Merlot in the 1990s. However, by 2015, Cabernet Sauvignon had once again become the most widely planted wine grape, with a total of 341,000 hectares (3,410 km2) under vine worldwide.

<span class="mw-page-title-main">Pinot noir</span> Red wine grape variety

Pinot noir is a red-wine grape variety of the species Vitis vinifera. The name may also refer to wines created predominantly from pinot noir grapes. The name is derived from the French words for pine and black. The word pine alludes to the grape variety having tightly clustered, pinecone–shaped bunches of fruit.

<span class="mw-page-title-main">Carignan</span> Red wine grape variety

Carignan is a red grape variety of Spanish origin that is more commonly found in French wine but is widely planted throughout the western Mediterranean and around the globe. Along with Aramon, it was considered one of the main grapes responsible for France's wine lake and was a substantial producer in jug wine production in California's Central Valley but in recent years, it has been reborn as a flagship wine for many cellars in the south of France as well as in Catalonia.

<i>Vitis vinifera</i> Species of flowering plant in the grape vine family Vitaceae

Vitis vinifera, the common grape vine, is a species of flowering plant, native to the Mediterranean region, Central Europe, and southwestern Asia, from Morocco and Portugal north to southern Germany and east to northern Iran. There are currently between 5,000 and 10,000 varieties of Vitis vinifera grapes though only a few are of commercial significance for wine and table grape production.

<i>Vitis rotundifolia</i> Variety of grape

Vitis rotundifolia, or muscadine, is a grapevine species native to the southeastern and south-central United States. The growth range extends from Florida to New Jersey coast, and west to eastern Texas and Oklahoma. It has been extensively cultivated since the 16th century. The plants are well-adapted to their native warm and humid climate; they need fewer chilling hours than better known varieties, and thrive in summer heat.

<span class="mw-page-title-main">Grenache</span> Red wine grape

Grenache or Garnacha is one of the most widely planted red wine grape varieties in the world. It ripens late, so it needs hot, dry conditions such as those found in Spain, where the grape is believed to have originated. It is also grown in the Italian island of Sardinia, the south of France, Australia, and California's Monterey AVA, Paso Robles, and San Joaquin Valley.

<span class="mw-page-title-main">Tempranillo</span> Variety of grape

Tempranillo is a black grape variety widely grown to make full-bodied red wines in its native Spain. Its name is the diminutive of the Spanish temprano ("early"), a reference to the fact that it ripens several weeks earlier than most Spanish red grapes. Tempranillo has been grown on the Iberian Peninsula since the time of Phoenician settlements. It is the main grape used in Rioja, and is often referred to as Spain's noble grape. The grape has been planted throughout the globe's wine regions.

<span class="mw-page-title-main">Ampelography</span>

Ampelography is the field of botany concerned with the identification and classification of grapevines, Vitis spp. Traditionally this has been done by comparing the shape and colour of the vine leaves and grape berries; more recently the study of vines has been revolutionised by DNA fingerprinting.

<span class="mw-page-title-main">Chlorosis</span> Medical condition in plants

In botany, chlorosis is a condition in which leaves produce insufficient chlorophyll. As chlorophyll is responsible for the green color of leaves, chlorotic leaves are pale, yellow, or yellow-white. The affected plant has little or no ability to manufacture carbohydrates through photosynthesis and may die unless the cause of its chlorophyll insufficiency is treated and this may lead to a plant diseases called rusts, although some chlorotic plants, such as the albino Arabidopsis thaliana mutant ppi2, are viable if supplied with exogenous sucrose.

<span class="mw-page-title-main">Catawba (grape)</span> Variety of grape

Catawba is a red American grape variety used for wine as well as juice, jams and jellies. The grape can have a pronounced musky or "foxy" flavor. Grown predominantly on the East Coast of the United States, this purplish-red grape is a likely cross of the native American Vitis labrusca and the Vitis vinifera cultivar Semillon. Its exact origins are unclear but it seems to have originated somewhere on the East coast from the Carolinas to Maryland.

<i>Vitis labrusca</i> Species of grapevine

Vitis labrusca, the fox grape, is a species of grapevines belonging to the Vitis genus in the flowering plant family Vitaceae. The vines are native to eastern North America and are the source of many grape cultivars, including Catawba, Concord, Delaware, Isabella, Niagara, and many hybrid grape varieties such as Agawam, Alexander and Onaka. Among the characteristics of this vine species in contrast to the European wine grape Vitis vinifera are its "slip-skin" that allows the skin of the grape berries to easily slip off when squeezed, instead of crushing the pulp, and the presence of tendrils on every node of the cane. Another contrast with European vinifera is the characteristic "foxy" musk of V. labrusca, best known to most people through the Concord grape. This musk is not related to the mammalian fox, but rather to the strong, earthy aromas characteristic of the grapes that were known by early European-American settlers in the New World. The term "foxy" became a sort of catchall for the wine tasting descriptors used for these American wines that were distinct from the familiar flavors of the European viniferous wines.

<span class="mw-page-title-main">Veraison</span> Onset of grape ripening in viticulture

In viticulture, veraison is the onset of the ripening of the grapes. The official definition of veraison is "change of color of the grape berries". Veraison represents the transition from berry growth to berry ripening, and many changes in berry development occur at veraison.

<i>Vitis</i> Genus flowering plants in the grape family Vitaceae

Vitis (grapevine) is a genus of 79 accepted species of vining plants in the flowering plant family Vitaceae. The genus is made up of species predominantly from the Northern Hemisphere. It is economically important as the source of grapes, both for direct consumption of the fruit and for fermentation to produce wine. The study and cultivation of grapevines is called viticulture.

<span class="mw-page-title-main">Phenolic content in wine</span> Wine chemistry

The phenolic content in wine refers to the phenolic compounds—natural phenol and polyphenols—in wine, which include a large group of several hundred chemical compounds that affect the taste, color and mouthfeel of wine. These compounds include phenolic acids, stilbenoids, flavonols, dihydroflavonols, anthocyanins, flavanol monomers (catechins) and flavanol polymers (proanthocyanidins). This large group of natural phenols can be broadly separated into two categories, flavonoids and non-flavonoids. Flavonoids include the anthocyanins and tannins which contribute to the color and mouthfeel of the wine. The non-flavonoids include the stilbenoids such as resveratrol and phenolic acids such as benzoic, caffeic and cinnamic acids.

This glossary of viticultural terms list some of terms and definitions involved in growing grapes for use in winemaking.

<i>Vitis arizonica</i> Species of grapevine

Vitis arizonica is a North American species of wild grape. It is a deciduous vine.

<span class="mw-page-title-main">Tempranillo blanco</span> Variety of grape

Tempranillo blanco is a white Spanish wine grape variety that is grown in the Rioja Denominación de Origen (DOC). It is a mutation of the red Tempranillo grape variety that is planted in Rioja. The white grape variety was discovered in a Tempranillo vineyard in the Rioja region by a wine grower in the late 20th century. In 2007, the Consejo Regulador of Rioja officially sanctioned the use of Tempranillo blanco in the DOC wines of Rioja.

Cascade is a red complex hybrid grape variety that was created by French viticulturist Albert Seibel in the early 20th century in Aubenas, Ardèche, in the Rhône Valley. It has been commercially available in North America since 1938 and has since been planted in Canada and the United States. However, in warmer climates the grape is highly susceptible to a number of grapevine viruses, which has discouraged plantings of the variety.

<span class="mw-page-title-main">Propagation of grapevines</span>

The propagation of grapevines is an important consideration in commercial viticulture and winemaking. Grapevines, most of which belong to the Vitis vinifera family, produce one crop of fruit each growing season with a limited life span for individual vines. While some centenarian old vine examples of grape varieties exist, most grapevines are between the ages of 10 and 30 years. As vineyard owners seek to replant their vines, a number of techniques are available which may include planting a new cutting that has been selected by either clonal or mass (massal) selection. Vines can also be propagated by grafting a new plant vine upon existing rootstock or by layering one of the canes of an existing vine into the ground next to the vine and severing the connection when the new vine develops its own root system.

References

  1. "International Grape Genome Program".
  2. Walker, Amanda R.; Lee, Elizabeth; Bogs, Jochen; McDavid, Debra A. J.; Thomas, Mark R.; Robinson, Simon P. (March 2007). "White grapes arose through the mutation of two similar and adjacent regulatory genes". The Plant Journal. 49 (5): 772–785. doi: 10.1111/j.1365-313X.2006.02997.x . PMID   17316172.
  3. "First white wine was a happy accident". Archived from the original on May 21, 2007.
  4. González, Rosa María. "Tempranillo en blanco y negro". Vinos al Mundo.com (in Spanish). Archived from the original on 2007-01-06. Retrieved 2007-04-11.